Members of this family are found only in the Geobacteraceae family species such as Geobacter sulfurreducens, Geobacter metallireducens, Pelobacter carbinolicus and Shewanella oneidensis. In Geobacter sulfurreducens, ompJ is the most abundant protein isolated from the outer membrane. Deletion of the ompJ gene in Geobacter sulfurreducens results in a strain that grew in fumarate, but could not grow with metals, such as soluble or insoluble Fe(III) and insoluble Mn(IV) oxide. The presumed effect of ompJ in extracellular electron transfer is indirect, as ompJ is required to keep the integrity of the periplasmic space necessary for proper folding and functioning of periplasmic and outer membrane electron transport components.